Today I needed to inject an Enum into a bean's constructor using Spring.
First I thought I'd need to write my own FactoryBean or 'better' a PropertyEditor.
Well no need, it is already nicely handled by the framework. After a bit of googling, I found the documentation in Appendix A of Spring's reference
And here is what actually works just fine. If I have the following enum:
public enum Language {
EN, FR
}
And the following class that I need to instantiate with Spring:
public class LocalisedLogger {
private final Language lang;
public LocalisedLogger(Language lang) {
this.lang = lang;
}
}
Then I can just configure it like this:
<beans> <bean id="logger" class="org.leberrigaud.example.LocalisedLogger"> <constructor-arg value="FR"> </constructor-arg> </bean> </beans>
That'it! Spring does the rest…
Thanks! Way better than the valueOf static method approach.
ReplyDeleteThanks for the example.
ReplyDeleteI have one question actually two..
1.Instead of passing
How can I pass Language.FR?
2.If I define the enum like
public enum Language {
EN("English"), FR("French");
private String name;
Language(String name){
this.name=name;
}
public getLanguageName(){
return name;
}
}
How can I use the function getLanguageName in spring?
Thanks
1. I don't know. I'm not sure why you would want to do this, since the enum type is already given by the constructor in our case.
Delete2. I don't know either. I don't see what is has to do with injecting enums. Why don't you inject the enum and then call the appropriate method. This will use stronger typing and is better IMHO.